Hypothalamus manufactures and secretes hypothalamic regulatory factors which control the secretion of adenohypophysial hormones. It is also the site for the synthesis of the two neurohypophysial hormones. Several of these compounds possess unique structural features essential for their biological activities - C-terminal carboxamide and N-terminal 5-oxoprolyl (pyroglutamyl) residues. The proposed research is aimed at characterizing the enzymatic processes responsible for the biogenesis of these terminal groups. It is proposed that the enzymes be purified, their properties such as specificities, reaction mechanism, molecular properties, and regulations be studied. Eventually these enzymes will be localized to the various cell types in the hypothalamus thus providing knowledge as to the precise sites of synthesis of these hormones.